Goncalves Priscila, Thompson Emma L, Raftos David A
Department of Biological Sciences, Macquarie University, Sydney, NSW, 2109, Australia.
Sydney Institute of Marine Science, Chowder Bay, Sydney, NSW, 2088, Australia.
BMC Genomics. 2017 Jun 2;18(1):431. doi: 10.1186/s12864-017-3818-z.
This study characterises the molecular processes altered by both elevated CO and increasing temperature in oysters. Differences in resilience of marine organisms against the environmental stressors associated with climate change will have significant implications for the sustainability of coastal ecosystems worldwide. Some evidence suggests that climate change resilience can differ between populations within a species. B2 oysters represent a unique genetic resource because of their capacity to better withstand the impacts of elevated CO at the physiological level, compared to non-selected oysters from the same species (Saccostrea glomerata). Here, we used proteomic and transcriptomic analysis of gill tissue to evaluate whether the differential response of B2 oysters to elevated CO also extends to increased temperature.
Substantial and distinctive effects on protein concentrations and gene expression were evident among B2 oysters responding to elevated CO or elevated temperature. The combination of both stressors also altered oyster gill proteomes and gene expression. However, the impacts of elevated CO and temperature were not additive or synergistic, and may be antagonistic.
The data suggest that the simultaneous exposure of CO-resilient oysters to near-future projected ocean pH and temperature results in complex changes in molecular processes in order to prevent stress-induced cellular damage. The differential response of B2 oysters to the combined stressors also indicates that the addition of thermal stress may impair the resilience of these oysters to decreased pH. Overall, this study reveals the intracellular mechanisms that might enable marine calcifiers to endure the emergent, adverse seawater conditions resulting from climate change.
本研究描述了牡蛎中因二氧化碳浓度升高和温度升高而改变的分子过程。海洋生物对与气候变化相关的环境压力源的恢复力差异，将对全球沿海生态系统的可持续性产生重大影响。一些证据表明，同一物种内不同种群的气候变化恢复力可能不同。B2牡蛎是一种独特的遗传资源，因为与同一物种（球蚶）未经选择的牡蛎相比，它们在生理水平上更能承受二氧化碳浓度升高的影响。在这里，我们对鳃组织进行了蛋白质组学和转录组学分析，以评估B2牡蛎对二氧化碳浓度升高的差异反应是否也延伸到温度升高的情况。
在应对二氧化碳浓度升高或温度升高的B2牡蛎中，对蛋白质浓度和基因表达有显著且独特的影响。两种压力源的组合也改变了牡蛎鳃蛋白质组和基因表达。然而，二氧化碳浓度升高和温度升高的影响并非相加或协同的，可能是拮抗的。
数据表明，将对二氧化碳有恢复力的牡蛎同时暴露于接近未来预测的海洋酸碱度和温度下，会导致分子过程发生复杂变化，以防止应激诱导的细胞损伤。B2牡蛎对组合压力源的差异反应还表明，热应激的增加可能会削弱这些牡蛎对酸碱度降低的恢复力。总体而言，本研究揭示了可能使海洋钙化生物能够承受气候变化导致的新出现的不利海水条件的细胞内机制。
